Two-dimensional ultrasound measurements vs. magnetic resonance imaging-derived ventricular volume of preterm infants with germinal matrix intraventricular haemorrhage

Neurosonography: Shaping the future of neuroprotection strategies in extremely preterm infants

This review aims to explore the current application of Cranial Ultrasound Screening (CUS) in the diagnosis and treatment of brain diseases in extremely preterm infants. It also discusses the potential role of emerging ultrasound-derived technologies such as Super Microvascular Structure Imaging (SMI), Shear Wave Elastography (SWE), Ultrafast Doppler Ultrasound (UfD), and 3D ventricular volume assessment and automated segmentation techniques in clinical practice. A systematic search of medical databases was conducted using the keywords "(preterm OR extremely preterm OR extremely low birth weight) AND (ultrasound OR ultrasound imaging) AND (neurodevelopment OR brain development OR brain diseases OR brain injury OR neuro*)" to identify relevant literature. The titles, abstracts, and full texts of the identified articles were carefully reviewed to determine their relevance to the research topic. CUS offers unique advantages in early screening and monitoring of brain diseases in extremely preterm infants, as it can be performed at the bedside without the need for anesthesia or special monitoring. This technique facilitates early detection and intervention of conditions such as intraventricular hemorrhage, white matter injury, hydrocephalus, and hypoxic-ischemic injury in critically ill preterm infants. Continuous refinement of the screening and follow-up processes provides reliable clinical decision-making support for healthcare professionals and parents. Emerging ultrasound technologies, such as SWE, SMI, and UfD, are being explored to provide more accurate and in-depth understanding of brain diseases in extremely preterm infants. SWE has demonstrated its effectiveness in assessing the elasticity of neonatal brain tissue, aiding in the localization and quantification of potential brain injuries. SMI can successfully identify microvascular structures in the brain, offering a new perspective on neurologic diseases. UfD provides a high-sensitivity and quantitative imaging method for the prevention and treatment of neonatal brain diseases by detecting subtle changes in red blood cell movement and accurately assessing the status and progression of brain diseases. CUS and its emerging technologies have significant applications in the diagnosis and treatment of brain diseases in extremely preterm infants. Future research aims to address current technical challenges, optimize and enhance the clinical decision-making capabilities related to brain development, and improve the prevention and treatment outcomes of brain diseases in extremely preterm infants.

Posthemorrhagic ventricular dilatation late intervention threshold and associated brain injury

OBJECTIVE

To systematically assess white matter injury (WMI) in preterm infants with posthemorrhagic ventricular dilatation (PHVD) using a high-threshold intervention strategy.

STUDY DESIGN

This retrospective analysis included 85 preterm infants (≤34 weeks of gestation) with grade 2-3 germinal matrix-intraventricular hemorrhage. Cranial ultrasound (cUS) scans were assessed for WMI and ventricular width and shape. Forty-eight infants developed PHVD, 21 of whom (intervention group) underwent cerebrospinal fluid drainage according to a predefined threshold (ventricular index ≥p97+4 mm or anterior horn width >10 mm, and the presence of frontal horn ballooning). The other 27 infants underwent a conservative approach (non-intervention group). The two PHVD groups were compared regarding ventricular width at two stages: the worst cUS for the non-intervention group (scans showing the largest ventricular measurements) versus pre-intervention cUS in the intervention group, and at term equivalent age. WMI was classified as normal/mild, moderate and severe.

RESULTS

The intervention group showed significantly larger ventricular index, anterior horn width and thalamo-occipital diameter than the non-intervention group at the two timepoints. Moderate and severe WMI were more frequent in the infants with PHVD (p<0.001), regardless of management (intervention or conservative management). There was a linear relationship between the severity of PHVD and WMI (p<0.001).

CONCLUSIONS

Preterm infants with PHVD who undergo a high-threshold intervention strategy associate an increased risk of WMI.

Degree of ventriculomegaly predicts school-aged functional outcomes in preterm infants with intraventricular hemorrhage

BACKGROUND

Greater ventriculomegaly in preterm infants with intraventricular hemorrhage (IVH) has been associated with worse neurodevelopmental outcomes in infancy. We aim to explore the relationship between ventriculomegaly and school-age functional outcome.

METHODS

Retrospective review of preterm infants with Grade III/IV IVH from 2006 to 2020. Frontal-occipital horn ratio (FOHR) was measured on imaging throughout hospitalization and last available follow-up scan. Pediatric Cerebral Performance Category (PCPC) scale was used to assess functional outcome at ≥4 years. Ordinal logistic regression was used to determine the relationship between functional outcome and FOHR at the time of Neurosurgery consult, neurosurgical intervention, and last follow-up scan while adjusting for confounders.

RESULTS

One hundred and thirty-four infants had Grade III/IV IVH. FOHR at consult was 0.62 ± 0.12 and 0.75 ± 0.13 at first intervention (p < 0.001). On univariable analysis, maximum FOHR, FOHR at the last follow-up scan, and at Neurosurgery consult predicted worse functional outcome (p < 0.01). PVL, longer hospital admission, and gastrotomy/tracheostomy tube also predicted worse outcome (p < 0.05). PVL, maximum FOHR, and FOHR at consult remained significant on multivariable analysis (p < 0.05). Maximum FOHR of 0.61 is a fair predictor for moderate-severe impairment (AUC 75%, 95% CI: 62-87%).

CONCLUSIONS

Greater ventricular dilatation and PVL were independently associated with worse functional outcome in Grade III/IV IVH regardless of neurosurgical intervention.

IMPACT

Ventriculomegaly measured by frontal-occipital horn ratio (FOHR) and periventricular leukomalacia are independent correlates of school-age functional outcomes in preterm infants with intraventricular hemorrhage regardless of need for neurosurgical intervention. These findings extend the known association between ventriculomegaly and neurodevelopmental outcomes in infancy to functional outcomes at school age. FOHR is a fair predictor of school-age functional outcome, but there are likely other factors that influence functional status, which highlights the need for prospective studies to incorporate other clinical and demographic variables in predictive models.

Intraparenchymal hemorrhage after serial ventricular reservoir taps in neonates with hydrocephalus and association with neurodevelopmental outcome at 2 years of age

OBJECTIVE

Decompressing the ventricles with a temporary device is often the initial neurosurgical intervention for preterm infants with hydrocephalus. The authors observed a subgroup of infants who developed intraparenchymal hemorrhage (IPH) after serial ventricular reservoir taps and sought to describe the characteristics of IPH and its association with neurodevelopmental outcome.

METHODS

In this multicenter, case-control study, for each neonate with periventricular and/or subcortical IPH, a gestational age-matched control with reservoir who did not develop IPH was selected. Digital cranial ultrasound (cUS) scans and term-equivalent age (TEA)-MRI (TEA-MRI) studies were assessed. Ventricular measurements were recorded prior to and 3 days and 7 days after reservoir insertion. Changes in ventricular volumes were calculated. Neurodevelopmental outcome was assessed at 2 years corrected age using standardized tests.

RESULTS

Eighteen infants with IPH (mean gestational age 30.0 ± 4.3 weeks) and 18 matched controls were included. Reduction of the ventricular volumes relative to occipitofrontal head circumference after 7 days of reservoir taps was greater in infants with IPH (mean difference -0.19 [95% CI -0.37 to -0.004], p = 0.04). Cognitive and motor Z-scores were similar in infants with and those without IPH (mean difference 0.42 [95% CI -0.17 to 1.01] and 0.58 [95% CI -0.03 to 1.2]; p = 0.2 and 0.06, respectively). Multifocal IPH was negatively associated with cognitive score (coefficient -0.51 [95% CI -0.88 to -0.14], p = 0.009) and ventriculoperitoneal shunt with motor score (coefficient -0.50 [95% CI -1.6 to -0.14], p = 0.02) after adjusting for age at the time of assessment.

CONCLUSIONS

This study reports for the first time that IPH can occur after a rapid reduction of the ventricular volume during the 1st week after the initiation of serial reservoir taps in neonates with hydrocephalus. Further studies on the use of cUS to guide the amount of cerebrospinal fluid removal are warranted.

Effects of early energy intake on neonatal cerebral growth of preterm newborn: an observational study

Current guidelines for preterm newborns recommend high energy nutrition soon after birth in order to limit growth retardation. However, long-term effects of this nutritional approach are still debated, and it has been demonstrated that cerebral growth depends on protein intake in early life. A negative impact of early high energy intake by parenteral nutrition (PN) has been reported for patients in critically ill conditions, observed in intensive care unit. We aimed at evaluating the impact of energy intake on cerebral growth in preterm neonates early in life. We included preterm newborns with gestational age < 32 weeks or birth weight (BW) < 1500 g. Measurement of cerebral structures was performed by cranial Ultrasonography (cUS) between 3 and 7 days of life (DOL, T0) and at 28 DOL (T1). We evaluated the relation between energy intake and cerebral growth in the first 28 DOL. We observed in 109 preterm newborns a significant (p < 0.05) negative correlation between energy intake received by PN and right caudate head growth (r = - 0.243*) and a positive correlation between total energy intake and transverse cerebellum diameter (r = 0.254*). Multivariate analysis showed that energy intake administered by enteral nutrition (EN), independently increased growth of left caudate head (β = 0.227*) and height cerebellar vermis (β = 0.415*), while PN independently affected growth of both right and left caudate head (β = - 0.164* and β = - 0.228*, respectively) and cerebellum transverse diameter (β = - 0.849*). The route of energy administration may exert different effects on cerebral growth in early life. High energy intake administered through EN seems to be positively correlated to cerebral growth; conversely, PN energy intake results in a poorer cerebral growth evaluated with cUS.

Ultrasonographic Estimation of Total Brain Volume: 3D Reliability and 2D Estimation. Enabling Routine Estimation During NICU Admission in the Preterm Infant

Objectives: The aim of this study is to explore if manually segmented total brain volume (TBV) from 3D ultrasonography (US) is comparable to TBV estimated by magnetic resonance imaging (MRI). We then wanted to test 2D based TBV estimation obtained through three linear axes which would enable monitoring brain growth in the preterm infant during admission. Methods: We included very low birth weight preterm infants admitted to our neonatal intensive care unit (NICU) with normal neuroimaging findings. We measured biparietal diameter, anteroposterior axis, vertical axis from US and MRI and TBV from both MRI and 3D US. We calculated intra- and interobserver agreement within and between techniques using the intraclass correlation coefficient and Bland-Altman methodology. We then developed a multilevel prediction model of TBV based on linear measurements from both US and MRI, compared them and explored how they changed with increasing age. The multilevel prediction model for TBV from linear measures was tested for internal and external validity and we developed a reference table for ease of prediction of TBV. Results: We used measurements obtained from 426 US and 93 MRI scans from 118 patients. We found good intra- and interobserver agreement for all the measurements. US measurements were reliable when compared to MRI, including TBV which achieved excellent agreement with that of MRI [ICC of 0.98 (95% CI 0.96-0.99)]. TBV estimated through 2D measurements of biparietal diameter, anteroposterior axis, and vertical axis was comparable among both techniques. We estimated the population 95% confidence interval for the mean values of biparietal diameter, anteroposterior axis, vertical axis, and total brain volume by post-menstrual age. A TBV prediction table based on the three axes is proposed to enable easy implementation of TBV estimation in routine 2D US during admission in the NICU. Conclusions: US measurements of biparietal diameter, vertical axis, and anteroposterior axis are reliable. TBV segmented through 3D US is comparable to MRI estimated TBV. 2D US accurate estimation of TBV is possible through biparietal diameter, vertical, and anteroposterior axes.

Randomized Controlled Early versus Late Ventricular Intervention Study in Posthemorrhagic Ventricular Dilatation: Outcome at 2 Years

OBJECTIVE

To compare the effect of intervention at low vs high threshold of ventriculomegaly in preterm infants with posthemorrhagic ventricular dilatation on death or severe neurodevelopmental disability.

STUDY DESIGN

This multicenter randomized controlled trial reviewed lumbar punctures initiated after either a low threshold (ventricular index of >p97 and anterior horn width of >6 mm) or high threshold (ventricular index of >p97 + 4 mm and anterior horn width of >10 mm). The composite adverse outcome was defined as death or cerebral palsy or Bayley composite cognitive/motor scores <-2 SDs at 24 months corrected age.

RESULTS

Outcomes were assessed in 113 of 126 infants. The composite adverse outcome was seen in 20 of 58 infants (35%) in the low threshold group and 28 of 55 (51%) in the high threshold (P = .07). The low threshold intervention was associated with a decreased risk of an adverse outcome after correcting for gestational age, severity of intraventricular hemorrhage, and cerebellar hemorrhage (aOR, 0.24; 95% CI, 0.07-0.87; P = .03). Infants with a favorable outcome had a smaller fronto-occipital horn ratio (crude mean difference, -0.06; 95% CI, -0.09 to -0.03; P < .001) at term-equivalent age. Infants in the low threshold group with a ventriculoperitoneal shunt, had cognitive and motor scores similar to those without (P = .3 for both), whereas in the high threshold group those with a ventriculoperitoneal shunt had significantly lower scores than those without a ventriculoperitoneal shunt (P = .01 and P = .004, respectively).

CONCLUSIONS

In a post hoc analysis, earlier intervention was associated with a lower odds of death or severe neurodevelopmental disability in preterm infants with progressive posthemorrhagic ventricular dilatation.

TRIAL REGISTRATION

ISRCTN43171322.

Early Protein Intake Influences Neonatal Brain Measurements in Preterms: An Observational Study

Introduction: To limit extrauterine growth restriction, recent guidelines on nutrition of preterm neonates recommended high protein intake since the first day of life (DOL). The impact of this nutritional strategy on the brain is still controversial. We aimed to evaluate the effects of protein intake on early cerebral growth in very low birth weight newborns.

Materials and Methods: We performed serial cranial ultrasound (cUS) scans at 3–7 DOL and at 28 DOL in very low birth weight newborns consecutively observed in the neonatal intensive care unit. We analyzed the relation between protein intake and cerebral measurements at 28 DOL performed by cUS.

Results: We enrolled 100 newborns (gestational age 29 ± 2 weeks, birth weight 1,274 ± 363 g). A significant (p < 0.05) positive correlation between enteral protein intake and biparietal diameter (r = 0.490^**), occipital–frontal diameter (r = 0.608^**), corpus callosum (length r = 0.293^*, genu r = 0.301^*), caudate head (right r = 0.528^**, left r = 0.364^**), and cerebellum (transverse diameter r = 0.440^**, vermis height r = 0.356^**, vermis width r = 0.377^**) was observed at 28 DOL. Conversely, we found a significant negative correlation of protein intake given by parenteral nutrition (PN) with biparietal diameter (r = −0.524^**), occipital–frontal diameter (r = −0.568^**), body of corpus callosum (r = −0.276^*), caudate head (right r = −0.613^**, left r = −0.444^**), and cerebellum (transverse diameter r = −0.403^**, vermis height r = −0.274^*, vermis width r = −0.462^**) at 28 DOL. Multivariate regression analysis showed that measurements of occipital–frontal diameter, caudate head, and cerebellar vermis at 28 DOL depend positively on protein enteral intake (r = 0.402^*, r = 0.305^*, and r = 0.271^*) and negatively by protein parenteral intake (r = −0.278^*, r = −0.488^*, and r = −0.342^*).

Conclusion: Brain development in neonatal life depends on early protein intake. High protein intake affects cerebral structures' measurements of preterm newborn when administered by PN. Positive impact on brain development encourages the administration of recommended protein intake mainly by enteral nutrition.